title: Perioperative indicators of hypocalcemia in total thyroidectomy: the role of vitamin D and parathyroid hormone.
abstract: BACKGROUND
  Hypocalcemia is a common complication of thyroidectomy. The aim of this study was to identify risk factors for this problem.
  
  
  METHODS
  This prospective analysis included 111 patients undergoing total or completion thyroidectomy. Preoperative vitamin D levels and postoperative day 1 parathyroid hormone levels were analyzed for their predictive effects on postoperative hypocalcemia.
  
  
  RESULTS
  Patients with ionized calcium <4.4 mg/dL had significantly lower mean parathyroid hormone levels than normocalcemic patients (13.0 vs 28.4 pg/mL, P < .001). Parathyroid hormone levels were also significantly lower in symptomatic patients (11.0 vs 28.4 pg/mL, P < .001). Preoperative vitamin D level, body mass index, gender, and pathologic findings were not associated with low calcium levels or symptoms of hypocalcemia.
  
  
  CONCLUSIONS
  Younger age and low postoperative parathyroid hormone levels are predictive of symptomatic hypocalcemia. A parathyroid hormone level outside of the reference range may indicate a need for more aggressive postoperative calcium supplementation and treatment with activated vitamin D. Older patients with normal postoperative parathyroid hormone levels may be safely discharged with appropriate calcium supplementation.
authors.affiliation: Department of Graduate Medical Education, Exempla Saint Joseph Hospital, 1835 Franklin Street, Denver, CO 80218, USA. Electronic address: eric.salinger@gmail.com.
authors.forename: Eric M
authors.initials: EM
authors.lastname: Salinger
authors.forename: John T
authors.initials: JT
authors.lastname: Moore
mesh_terms: D002118:Calcium / Q000097:blood; D005260:Female; D006801:Humans; D006996:Hypocalcemia / Q000097:blood / Q000175:diagnosis* / Q000209:etiology; D008297:Male; D008875:Middle Aged; D010281:Parathyroid Hormone / Q000097:blood*; D011183:Postoperative Complications; D011184:Postoperative Period; D011379:Prognosis; D011446:Prospective Studies; D012307:Risk Factors; D013965:Thyroidectomy / Q000009:adverse effects*; D014807:Vitamin D / Q000097:blood*
chemical_list: D010281:Parathyroid Hormone; D014807:Vitamin D; D002118:Calcium
keywords: Completion thyroidectomy; Postoperative hypocalcemia; Postoperative parathyroid hormone levels; Prospective trial; Total thyroidectomy; Vitamin D